The study explored the trajectories of psychological well-being in older adults preceding the development of mild cognitive impairment (MCI) and dementia. 

It aimed to understand how psychological well-being and its components change over time in individuals who transition from being cognitively healthy to experiencing MCI and dementia.

Poor psychological well-being is linked to increased dementia risk, but changes over time are unclear.

The study followed 910 cognitively intact older adults for up to 14 years, measuring psychological well-being and its components annually.

Those who developed mild cognitive impairment (MCI) experienced faster declines in overall psychological well-being, noticeable two years before diagnosis.

Specific components like purpose in life and personal growth declined earlier: 3 years and 6 years before MCI diagnosis, respectively.

After the MCI diagnosis, most well-being components declined at similar rates, except for "positive relations with others," which declined faster.